The ever increasing use of computer terminals in the work place and as a means for entertainment has resulted in a corresponding increase in asthenopia, i.e. eyestrain, eye irritation, and general eye discomfort in computer users generally related to "dry eye". Many attempts have been made to solve this problem. The attempts include the use of non-glare screens and various color combinations of the display. All of these attempts have failed.
Recent exhaustive studies by the medical profession have resulted in a breakthrough with respect to understanding the problem. Medical investigators have determined that a computer user staring at a display terminal blinks at a rate which is significantly below the norm for that individual. This reduction in the rate at which a person blinks causes a corresponding reduction in the frequency at which the eye is cleansed and bathed by secretions from the tear duct. This leads to a dry eye syndrome manifested as discomfort, irritation and fatigue. In extreme cases, the irritation can lead to more serious problems affecting the health of the eyes.
One factor leading to the reduced blink syndrome is that a video display terminal changes on a micro level as single letters or numbers are added to the screen by an operator. This creates a gradual or micro change to the visual field which will not stimulate a blink response. What is required to cause reactive blinking is a sudden change in the visual field on a macro level such as might be caused by a strobe light.
The co-pending patent application, Ser. No. 08/102,224, of the present inventors teaches the use of involuntary blink reactions caused by macro events to reduce eye strain. That approach has proved satisfactory for most computer terminal operators, but for others using a computer for purposes requiring deep concentration, the macro events, even when subliminal, are an unacceptable distraction.